The general aim of the program continues to be improvements in the clinical application of basic cardiac electrophysiology. Animal experimentation, computer modeling and observations on patients are being employed. One of the major specific objectives is development of an improved electrocardiographic examination for clinical use. A large array of electrodes has been employed to determine body surface potential patterns and smaller arrays of electrodes in which redundant information has been reduced have been developed. Evidence supporting the possibilities of regional cardiac examination and of recognizing cardiac states at high risk of ventricular arrhythmias has been obtained. Other areas of investigation are cardiac electrophysiologic effects of the autonomic nervous system, the physiologic mechanisms and functional consequences of cardiac arrhythmias, electrophysiologic effects of ischemia and physiologic bases of the body surface electrocardiogram.